As a first background technique of the present technique, an image region classification apparatus is disclosed in Patent Document 1. The image region classification apparatus according to the first background technique includes histogram creating means for creating a histogram of an image at a lattice point in color space with each color component as an axis on the basis of the image constituted by a plurality of color components, histogram displaying means for displaying the histogram created by the histogram creating means, by an object of a size corresponding to a histogram value, and cluster classifying means for classifying all the lattice points of the histogram created by the histogram creating means using a plurality of representative values.
According to the image region classification apparatus of the first background technique, since the histogram of an image is created in the lattice points in the color space with each color component as the axis on the basis of the image to be classified, and this histogram is displayed by the object of a size corresponding to the histogram value, the histogram value in the color space can be visually recognized by an operator, so that the operator can set cluster classification adjusted suitably with reference to the displayed object, and appropriate and prompt color classification can be performed.
As a second background technique of the present technique, an image processing method is disclosed in Patent Document 2. The image processing method of the second background technique is an image processing method for calculating a parameter to classify at least a portion of pixels in an input image to a cluster having a similar hue, and the method includes the steps of: clustering at least the portion of the pixels in the input image based on its color difference; calculating hue values of the pixels; clustering the hue values of the pixels by dividing a hue circle representing a hue into a variable division number of division clusters, and varying a range of the hue value corresponding the division cluster by rotating the divided hue circle at a variable rotation angle; calculating an evaluation value based on the result of the clustering; determining the parameter by varying the division number and the rotation angle to optimize the evaluation value; and reclassifying the clustering result corresponding to the color difference based on the parameter. According to the image processing method of the second background technique, tuning is not required, and color image segmentation close to a human sense can be performed.
As a third background technique of the present technique, a pattern recognition system is disclosed in Patent Document 3. The pattern recognition system in the third background technique includes pattern data obtaining means for obtaining a state of a pattern to be recognized, input data editing means for forming a cluster showing a state of a feature region of data distribution obtained by the pattern data obtaining means, based on this distribution, feature vector extracting means for extracting a feature vector showing the feature in the cluster formed by the input data editing means of the data obtained by the pattern data obtaining means, wherein the pattern is recognized by comparing a feature vector extracted by the feature vector extracting means at a learning stage, with the feature vector extracted by the feature vector extracting means from the portion in the cluster generated by the input data editing means at the learning stage in the data distribution obtained by the pattern data obtaining means at a recognition stage. The pattern recognition system includes cluster adjusting means for varying the state of the cluster formed by the input data editing means at the learning stage according to the variation of the data distribution obtained by the pattern data obtaining means at the recognition stage.
According to the pattern recognition system of the third background technique, even when the data state is varied due to the influence of the environmental change in spite of the fact that the learned pattern is attempted to be recognized at the time of pattern recognition to recognize the learned pattern, the collection state of the data can be varied based on the environmental change, so that the pattern can be recognized without performing a relearning process even when the environment is changed.                [Patent Document 1] Japanese Laid-Open Patent Publication No. 2002-190018        [Patent Document 2] Japanese Patent No. 3708042        [Patent Document 3] Japanese Patent No. 3025986        